2024年3月15日发(作者：南昌江安2021数学试卷)

Abstract

Thispaperpresentsonecasestudytoillustratehowprobabilitydistributionand

geneticalgorithmandgeographicalanalysisofserialcrimeconductedwithina

quesare

illustratedforpredictingthelocationoffuturecrimesandfordeterminingthepossible

residenceofoffendersbasedonthegeographicalpatternoftheexistingcrimesand

quantitativemethod,undthatsuchmethodsarerelativelyeasyto

implementwithinGISgivenappropriatedatabutrelyonmanyassumptionsregarding

offenders’omesuccesshasbeenachievedinapplyingthe

techniquesitisconcludedthatthemethodsareessentiallytheory-lessandlack

researchintotheevaluationofsuchmethodsandinthegeographic

behaviourofserialoffendersisrequiredinordertoapplysuchmethodsto

investigationswithconfidenceintheirreliability.

uction

ThisseriesofarmedrobberiesoccurredinPhoenix,Arizonabetween13September

and5December1999andincluded35robberiesoffastfoodrestaurants,hotelsand

enderswerenamedthe“Supersonics”bythePhoenixPolice

DepartmentRobberyDetailasthefirsttworobberieswereofSonicDrive-In

he35

th

robbery,theoffendersappeartohavedesistedfromtheir

asfortheoffendersto

targetbusinesseswheretheycouldeasilygainentry,pullonaskimaskorbandanna,

confrontemployeeswithaweapon,orderthemtotheground,emptythecashfroma

safeorcashregisterintoabagandfleeonfootmostlikelytoavehiclewaitingnearby.

Whileitappearsthattheoffendersoccasionallyworkedaloneorinpairs,theMO,

weaponsandwitnessdescriptionstendtosuggestagroupofatleastthreeoffenders.

Theobjectiveoftheanalysiswastousethegeographicdistributionofthecrimesto

predictthelocationofthenextcrimeinanareathatwassmallenoughtobesuitable

orkingwitha

popularcrimeanalysismanual(Gottleib,ArenbergandSingh,1994)itwasfoundthat

theprescribedmethodproducedtargetareassolargethattheywerenotoperationally

r,theapproachwasattractiveasitrequiredonlybasicinformationand

tifyareasthatweremoreusefulforthe

RobberyDetail,itwasdecidedtouseasimilarapproachcombinedwithother

wasa“live”case,

newcrimesandinformationwereintegratedintotheanalysisasitcametohand.

tion

Inordertomodifythemodelexisted,weapplyserialnewassumptionstotheprinciple

retheassumptions:

1

.Criminalsprefersomethingaboutthelocationswherepreviouscrimeswere

.

Wesupposedthecriminalshaveagreateropportunitytoranawayiftheycommittedcommitted.

tion,thecriminalsprobably

choosepreviouskillsiteswheretheirtargetpotentialvictimsliveandwork.

2.

Offendersregarditsafertocrimeintheirpreviouskillsiteastimewent

truethatthesitewouldbeseverelymonitoredbypolicewhenashortterm

crimehappenedandconsequentlythecriminalwouldsufferariskofbeingarrestedin

entionedabove,thepolicewouldreducethefrequencyof

examiningthepreviouskillsitesastimewentby.

a

reasonableassumptionsinceitisprobablyinsecuretocrimeinthesitethatstaysfar

awayandthatcostsanamountofenergytoescapeandaddstheopportunitytobe

salsoimpossibletocrimeinthesite

near

result,wecanmeasureaoptimaldistanceinseriesperpetrations.

methatallthecaseinthemodelare

waythecriminalis

subjecttotheassumptionsmentionedaboveduetohisinsufficientpreparation.

\'

movementsunconstrained.

Becauseofthedifficultyoffindingreal-world5.

CriminalsCriminals\'

distancedata,weinvokethe“Manhattanassumption”:Thereareenoughstreetsandsidewalksina

sufficientlygrid-likepatternthatmovementsalongreal-worldmovementroutesisthesameas

“straight-line”monstratedthatacross

severaltypesofserialcrime,theEuclideanandManhattandistancesareessentially

interchangeableinpredictinganchorpoints.

dictionofthenextcrimesite

3.1Themeasureoftheoptimaldistance

Duetothefactthatthementaloptimaldistanceofthecriminalisrelatedtowhetherheisacareful

personornot,s,theoptimaldistancewill

r,suchdistanceshouldbereflectedonthedistancesofthe

ethatthecoordinatesofthencrimesitesisrespectively

(

x

1

,

y

1

)

、

(

x

2

,

y

2

)

、……、

(

x

n

,

y

n

)

,anddefinethedistancebetweenthe

i

th

crimesiteandthe

j

th

one

as

D

i,

j

.ThedistanceabovewefirstconsideritasEucliddistance,whichis:

D

i

,

j

=(

x

i

−

x

j

)

2

+(

y

i

−

y

j

)

2

Withthat,weareabletomeasurethedistancebetweenthe

n

th

crimesiteandthe

n-1

th

one

respectively.

Accordingtotheassumption2,thecriminalbelievesthattheearliercrimesiteshavebecamesafer


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江安,南昌,数学试卷,作者